This invention relates to hydraulic control systems for steam turbines of the type used for marine use or for power generation, and more particularly to combination steam or speed and tripping control systems for such turbines. The high pressures and high speeds present in modern turbine operation require control systems for the supply of steam to the turbine which are reliable, positive in operation, and readily accessible for actuation by the operator. Failure of protective controls for the turbine could lead to extensive damage to the turbine and surrounding buildings, or to a ship in the case of marine use. Hydraulic control systems are commonly used for turbine control and consideration must be given in their design to operation and reliability. However, it is desirable to optimize the ease of control while insuring and improving control system operation, particularly in regard to trip throttle valve control, of the steam valve which controls the main steam flow to the turbine, and which is used to shut the turbine down in the event of malfunctions of the system. With the growing complexity of turbine control systems, it is desirable to minimize the number of controls and to facilitate ease of operation whenever possible. This is particularly true for controls relating to overspeed or manual trip and reset of the turbine.